Shock absorber



Nov. 24 1925.

E. FLENTJE SHOCK ABSORBER Filed Dec. 29. 1924 2 Sheets-Sheet 2 lnvenTor. Erns Flen'je Patented Nov.v 24, 1925..

UNITED STATES 1,562,879 .PATENT OFFICE.

ERNST FLENTJE, QF CAMBRIDGE, MASSACHUSETTS.

SHOCK ABSORBEIL Application mea December 2s, 1924. serial No. 758,637.

To all whom t ma? concern,.-

Be it known that ERNST FLENTJE, a citizen of the'United States, and resident of Cambridge, county of Middlesex, State of Massachusetts, have invented an Improvement in Shock Absorber-s, of which the fol-y lowing description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing` like parts.

This invention relates to shock absorbers such as are used on automobiles to counteract or prevent violent recoil of the springs after they have been compressed, and particularly to shock absorbers of the type including a cylinder secured either to the axle or the chassis, usually the axle, and a valved piston within the cylinder having a piston rod extending through the end of the cylinder and connected to the chassis.

One of the objects of my present invention is to provide an improved shock absorber of this type which has a minimum overall length and which is, therefore,adapted to be used on low hung cars.

Other objects of the invention are to-provide a novel shock absorberof this type in which the retarding action of ther piston in the `cylinder is secured partly by the use of a liquid in the cylinder and partly by the use of air, to provide a shock absorber with an improved stufHng box for the piston rod and an improved means for enclosing and protecting the portion of the piston rod exterior to the cylinder and otherwise to improve shock absorbers all as will be more fully hereinafter set forth.

1n order to givean understanding of the invention I have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the' appended claims.

of a device emthrough which are adapted to be closed by a valve 4, herein shown ashaving an annular shape which surrounds the piston rod 5. The valve is yieldingly held to its seat by means of springs 6 which encircle Ipins 7 that are' secured to the valve and extend through the piston. The cylinder 1 contains some suitable checking fluid 8 such for instance as oil or glycerine and the valve herein shown permits the piston to' move downwardly freely but closes when the piston moves upwardly.

The cylinder is connected at its lower end to the axle of the automobile by means which will presently be described, and the piston rod 5 extends through the upper end of the cylinder and is'connected to the frame kor chassis 9 of the automobile so that as the springs of the automobile Hex the piston will move up and down in the cylinder as usual in shock absorbers of this type.

'The piston rod 5 is hollow and is provided with by-pass ports 10 and 11 which form a communication between the cylinder space below the piston and that above the piston. These ports are adapted to be controlled as to their area by a iston valve 12 which is adjustable longitudinally of the hollow piston rod and is provided with a stem 13, the end 14 of which extends through the end of the piston rod and has screw-threaded engagement therewith, said end being provided with la wrench-receiving portion 15 for recciving a wrench or other tool for adjusting the valve.

rlhe parts thus far described are or may be all as usual in shock'absorbers of this type and it will be understood that when the springs of the automobile flex so that the axle and body move toward each other the piston will be moved downwardly in the cyllnder and the valve 4 will open thus allowing a free passage of the checking liquid both through the ports 3 and through the bypass ports 10 and 11. When the spring begins to recoil, however, and the iston starts to move upwardly the valve 4 will close and the upward movement of the iston is then determined by the rate at wh1ch the liquid can flow through the by-pass ports 10 and 11 and the area of these ports may be adjusted type which can be used Withicars of this class. I secure this object by employing novel means for connecting the piston rod andcylinder to the chassis and axle of the automobile respectively which does not add `anything to the over-all length of the device.

\The cylinder 1 is provided at its lower end with a head N16 which is shown as screwthreaded thereto and said head is formed with a lateral extension 17 to which is flex ibly connected a horizontally-extending stud 18 that is secured in a bracket 19 which in turn is adapted to be secured to the car axle. The stud 18 is provided at its end with a ball 2() and this ballA is received between two socketed bearing blocks 21, 22. The bearing vblock 21 is carried in a seat or recess formed in the lateral extension 17 and the block 22 is carried in a recess@ formed in a cross head 23. The cross head is connected to the eX tension 17 by means of two bolts 24 that extend vertically through the cross head and are. situated on opposite sides of the ball 20.

I will preferably employ springs25 which encircle the bolts 24 and are situated between the cross head 23 and the heads 26 ofthe bolts. These springs introduce a yielding element into the connection so that the ball 2() is retained between two seats capable of having a slight yielding movement relative to each other.- Provision is made for lubricating this ball bearing by introduction of suitable lubrication through the connections p 87 indicate vertically-extending pins which ar'e anchored at their lower ends in recesses in the extension 17 and at their upper `ends in recesses in the cross head 23. These pins are situated on opposite sides of the stud 18 and serve to limit the lateral swinging movement of the stud. v

A similar construction is employed in the connection between the pistonrod and the chassis 9. The upper end of the piston rod has a head 28 secured thereto which is provided with a laterally-'extending arm 29, the vlatter carrying Qn'itsunder face a socket 'bearing member-BO that receivesthe ball end 31 of a laterally-extending stud 32. This ball is confined between the socket member 3() and a similar socket member 33 that is carried by a cross head 34, said cross head being yieldingly connected to thef arm 29' by means of bolts 24 and springs 25 similar to those above described with reference to the cross head 23.

The stud`32 is shown as anchored in an -angle `.iron member 35 which in turn is secured to an angle iron bracket 36 that is bolted to the `sill 9 of the chassis by a bolt 37. The members 35 and 36 are connected as n by means of bolts 38. vWith this coniiattaching the; device to the axle'and auto'l mobile .-gframj do not extend beyond the ends tion the brackets and other means for* and socket connection provides a connection which is sufficiently flexible to accommodate any relative movement between the axle and body of an automobile without bringing any unnecessary strain on the parts.

The stufling box which is used for packing the piston rod is ot' novel construction. It comprises a cup-shaped member 39 which is set into the upper end of the cylinder and is provided with a flange 40 resting on the end of the cylinder, said member being held in place by the cap 41'which is provided with the screw-threaded flange 42 that is screw-threaded to the cylinder.

43 indicates packing situated in the lower end of the member 39 and 44 is a packing gland which engages this packing'and holds it in position. A second packing 45 is located at the upper end of themember 39 and is confined between the head 41 and another packing gland 46 that is also slidably mounted on the piston rod.

47 indicates a spring situated between the two packing glands46, 44, said spring tending to force the packing glands away from acking rings 43 and 45.

With this -construction a double packing is provided and both packing rings are automatically maintained tightly compressed about the piston by means of the spring 47.

The shock absorber herein shown embodies a construction by which the portion of the piston rod 5 which extends beyond the cylinder is protected and by which an air cushion is provided which augments the action of the liquid in checking the recoil of the spring.

The head 28 which is secured to the 'end of the piston rod has a cylinder .or sleeve 48 screw-threaded thereto at 49, said sleeve fitting tightly over the flange 42 and the cylinder cap 41. This cylinder 48 is long enough so that it will not be withdrawn from the cap 41 even when the piston is at the upper end of its limit. This cylinder will slowly escape between ment of the piston. Similarly, when the spring recoils and the piston moves upwardly a suction will be produced in the chamber 81 and air will seep into said chamber slowly between the walls. of the cylinder 48 and the iiange 412. A pneumatie element is thus introduced into the shock absorber which (fo-operates with the liquid to ensure smooth action of the device.

In order to keep the walls of the cylinder 48 lubricated I propose to place vin saidy chamber 81 a quantity of fibrous material ye() such as cotton waste which may be saturated with lubricant and Which-Wi11 furnish sufficient lubrication for'lubricating the cylinder walls.

The head 28 is shown as having a filling opening 79 therein which is closed by a plug 78. The purpose of this opening is for introducing lubrication to the chamber as needed.

This cylinder 48 not only provides the pneumatic element above referred yto but it also acts as a means for protecting the portion of the piston rod which projects beyond the cylinder and keeping said'portion free from dust and dirt. p v

The cylinder cap is shown as having a bevelled extension 77 which acts to clean the piston rod as it moves downwardly.

In a device of this sort it is desirable that the closing of the valve 4 in the piston should be accomplished Without any unneces sary noise. ITo provide a quietly closing valve I secure to the under side of the latter two disks 50 and 5l of fibre or some similar nonsmetallic material and I place `a wire 52 between the two disks adjacent the peripheries thereof. This wire tends .to separate the disks slightly and to bendtlii'e outer edge ofthe lower disk downwardlyas shown at When, therefore, the valve seats this lower edge of the non-metallic disk 53 will strike the piston with a slightly yielding or cushioned movement. This cushioned movement together with the non-n1etallic nature of the washer will provide a substantially noiseless closing valve.

I claim: Y

1. A shock absorber for automobiles comprising a cylinder, a valved piston therein having a piston rod, said cylinder having at one end a laterally-extending' arm, a head secured to the end of the piston rod and provided with a laterally-extending arm, a`

stud extending horizontally from each arm, each stud having a ball-and-socket connection with its arm, and means for connecting one stud to the chassis of an automobile and the other stud to the axle thereof.

2. A shock absorber comprising a cylinder, a valved piston therein having a piston rod, a cap closing one end of the cylinder and having a laterally-extending arm, a head secured to the end of the piston rod sleeve secured to the end and also having a laterally-extending arm, a lun'izouial stud having a ball-andsocket connection with each arm, and means for connecting one stud to the axle of the automobile and the other to the chassis thereof. 3. A shock absorber' for automobiles comprising a cylinder', a valvedv piston therein having a piston rod, a cap closing one end of the cylinder and provided with a laterallyextending arm, a head secured to the end of the piston rod and also having a laterallyextending arln, each of said arms being pro vided with two socket bearing members, a stud having a ball received between each pair of socket members, and means for connecting onestud to the axle and the other to the frame of an automobile.

4. In a shock absorber, the combination with a cylinder, of a valved piston therein vpacking-receiving chambers and a spring interposed between sald glands and holding each yieldingly against the corresponding packing.

6. A shock absorber comprising a c linder, a valved piston therein having a plston rod, a stuffing box for the piston rod comp-rising a cup-shaped member set into the end of the cylinder, a cap screw-threaded to the cylinder, a packing ring in the lower end of the cup-shaped member, another pack-` ing ring in the cap, twopacking rings and a spring interposed between the glands.

7. A shock absorber comprising a cylinder, a valved piston therein having a piston rod, a cap for the'cylinder through which the piston rod extends, said cap having a central boss or raised portion, a protecting sleeve secured to the end of the piston rod and slidably `fitting the cylinder cap, said sleeve forming with the cap an air chamber that assists in retarding the movement of the piston, and absorbent material containing lubricant between the boss of the cylinder head and the walls of the sleeve, said absorbent material providing lubrication for the sleeve walls.

8. A shock absorber comprising acylinder, a valved pisto-n therein having a piston rod, a cap for the cylinder thro-u h which the piston rod extends, said cap aving a central boss or raised portion, a protecting of the piston rod and slidably ittin the cylinder cap, saido tion for the sleeve walls, said cap having a sleeve forming Wit the cap an air chambevelled extension immediately surrounding ber that'assists in retarding the movement the piston rod and which operates as a 10 of the piston, and absorbent material eoncleaner for the latter.

taining lubricant between the boss of the In testimony whereof I have signed my cylinder head and the walls of the sleeve, name to this specication. said absorbent material providing lubrica- ERNST FLENTJE. 

